The present invention relates to devices for delivering, injecting, infusing, administering or dispensing a substance, and to methods of making and using such devices. More particularly, it relates to a portable medical device or apparatus for dispensing a fluid drug and, in some embodiments, for automatically dispensing the fluid drug.
Devices for automatically and continuously dispensing fluid drugs are often used with patients who continuously require a drug which can be exclusively administered subcutaneously, wherein the requirement varies throughout the day. Specific application scenarios include, for example, certain pain therapies and the treatment of diabetes mellitus, in which computer-controlled administering devices which can be worn on the body are used, wherein there is a fundamental need for the administering device to have a low weight and a minimum volume to enable it to be worn comfortably and discreetly.
Conventional, extra-corporeal infusion devices for therapeutic use which are carried on the body or in clothing by a wearing system are common in the prior art. While the patient is sleeping, they are in most cases placed on or in a storage location next to the bed and remain connected to the body via a catheter supply line, thus maintaining the administering of fluid.
Miniaturised infusion devices have recently become available which are attached directly to the surface of the skin. The administering device is attached to the surface of the skin and the administering cannula is inserted into the body tissue by the patient personally. Once such an infusion device has been attached to the surface of the skin, it generally adheres to the body for 4 to 5 days and is then completely or partially disposed of.
Both infusion devices which are attached to the surface of the skin and conventional infusion devices exhibit situation-dependent advantages and disadvantages specific to their type. Thus, for example, it is desirable during daily use by the patient for the infusion device to be temporarily removable, at least partially, to, for example, pursue a sporting activity without hindrance or to not expose precision parts or electronic components of the administering device to undesirable contact with water in the course of showering or bathing.
A conventional administering device can be temporarily removed by temporarily disconnecting the catheter tube and suitably sealing the coupling locations. Single-use auxiliary devices or features, for example insulin ampoules, batteries and/or catheters, can also be replaced or exchanged without any problems in the conventional administering devices, since the devices are designed for a long service life.
By contrast, administering devices which are worn on the surface of the skin typically may not be temporarily disconnected nor can parts of the device be exchanged due to their design which is consistently oriented toward single use and low production costs. Temporarily disconnecting them from the body in a way suitable for the patient, for physical activities such as, for example, sports, swimming or cleaning the body, is not possible. Even if administering devices which are worn on the surface of the skin are significantly miniaturised, the patient remains restricted in their freedom of movement, since a certain component volume is still arranged on the body, and a static imbalance limits the wearing comfort. There is also the danger of the apparatus detaching from the body because it is insufficiently adhered to the body, for example when attached by means of a plaster, or of the apparatus being torn from the body by sudden movements. The injection locations and wearing locations are also limited for this design. Nonetheless, such devices provide an inconspicuous, discreet way of being worn and short fluid connections which may be cited as advantages of administering devices which are worn on the surface of the skin.
EP 1527792 A1 describes an administering device which can be attached on the surface of the skin, but which cannot be temporarily disconnected.